Re: INITRANS and MAXTRANS are confusing me?

From: Howard J. Rogers <howardjr2000_at_yahoo.com.au>
Date: Wed, 12 Mar 2003 18:06:38 +1100
Message-ID: <pan.2003.03.12.07.06.36.276949@yahoo.com.au>

On Tue, 11 Mar 2003 23:07:42 +0200, Tanel Poder wrote:

> Howard,
>
> Was this "process ID" just a simplification you used, for making the idea
> more understandable?
>

>> Basically, your process ID (unique to your session) is stored in the
>> transaction slot. The row piece at the start of each row then stores the
>> transaction slot number. Now I have a link from a row, back to who
>> precisely has it locked.

>
> Because per Oracle terminology, I'd say no process or session ID's are
> stored in data nor rbs blocks. It's more like transaction identifiers which
> just identify a transaction slot number in a rollback segment (+ sequence
> number), also undo block addresses in ITLs, which point to the last undo
> block for a transaction in a given block.
> In row header, there's a one byte pointer to a ITL entry in the same block.
>
> So, afrter a crash, theres no information available, whith process or
> session was responsible for a change, we only know transaction IDs, which
> translate to bunch of undo blocks in right order - an undo chain.
>
> Either you were simplifying a lot, or I got something wrong from your post.
>

I was simplifying a lot. Hence the use of the word "basically" right at the beginning.

HJR
> Thanks,
> Tanel.
Received on Wed Mar 12 2003 - 01:06:38 CST